Hand-operated punchers, used to punch holes in paper and other sheet materials such as cardboard, leather, fabric, plastics, and similar materials, are well-known. Punchers are primarily being used to bind these sheets in a binder. There are several different binder standards. The most popular in the US are the three-hole binders where the distance between two adjacent rings is 4.25″ and the two-hole binders where the distance between binder rings is 2.75″.
Numerous adjustable combination punchers are known to the art where the same punching sets could be used to punch two or three holes at the time. However, all these punchers need to be readjusted in order to switch from a three-hole punch to a two-hole punch, and vice-versa.
In the U.S. Pat. No. 2,534,094, J. A. Yerkes discloses an adjustable paper puncher where 11 removable punch members can be inserted into all or any of the available 11 holes. In this puncher, switching from two to three holes requires a readjustment by pulling and reinserting of the punch members.
In the U.S. Pat. No. 4,688,457, Hildaur L. Neilsen discloses an adjustable paper puncher where each punch set is having a pivoted spacer that can be turned to engage the particular set with a lever. In this puncher, the switching from two to three holes requires a readjustment accomplished by turning the pivoted spacer.
In the U.S. Pat. No. 4,724,734, Park-Son Hse discloses a multipurpose puncher that includes a pair of single-hole stationary puncher assemblies positioned separately on a base, and a movable puncher assembly mounted slidably between these stationary assemblies. This puncher permits to switch from a single-hole punch and a two-hole punch without making any changes to a puncher. But switching from a two-hole to three-hole punch requires a readjustment.
All these combination punchers require a readjustment in order to switch from two-hole punch and three-hole punch. Placing two separate punchers, a two-hole and a three-hole puncher, side-by-side on a common platform has never made much sense because such a combination puncher would have nearly as many components as two separate units and have the same footprint as the total footprint of two punchers.